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United States Patent |
5,168,800
|
Margolis
|
December 8, 1992
|
Quality enhancing treatment for ground heat product
Abstract
A method and apparatus for eliminating fat from a formed ground meat
product while maintaining desireable texture and other eating qualities,
comprising the steps of placing the product on a support member configured
to promote the flow of fat away from the product; bringing the product to
a temperature at which a substantial proportion of the fat contained in
the meat is liquified; and compressing the product against the support
member only after the product has reached the temperature at which a
substantial portion of the fat contained in the meat is liquified, by
applying a rolling pressure which repeatedly traverses the product in a
plane parallel to the support member for a period and at a pressure level
sufficient to exude a substantial portion of the liquified fat from the
product. During at least part of the time when rolling pressure is
applied, a non-fat liquid is supplied to the top surface of the product.
Inventors:
|
Margolis; Geoffrey (12229 Falkirk La., Los Angeles, CA 90049)
|
Assignee:
|
Margolis; Geoffrey (Los Angeles, CA)
|
Appl. No.:
|
537641 |
Filed:
|
June 14, 1990 |
Current U.S. Class: |
99/495; 99/349; 99/534; 100/73; 100/125; 100/158R; 100/210 |
Intern'l Class: |
B30B 009/20; A23N 001/00; A23L 001/31 |
Field of Search: |
100/37,68,71,73,106,110,116,121,125,158 R,210
99/349,495,534,457
|
References Cited
U.S. Patent Documents
452213 | May., 1891 | Castanos | 100/73.
|
456248 | Jul., 1891 | Curtis | 99/457.
|
641084 | Jan., 1900 | Cross | 100/210.
|
890079 | Jun., 1908 | Maggini | 100/210.
|
1620567 | Mar., 1927 | Navarre | 100/210.
|
1656662 | Jan., 1928 | Carter et al.
| |
1933022 | Oct., 1933 | Meeker | 100/121.
|
2075407 | Mar., 1937 | Schwartzman.
| |
3125019 | Mar., 1964 | Ackerman | 100/158.
|
3457853 | Jul., 1969 | Morley.
| |
3603240 | Sep., 1971 | McCarthy.
| |
3682655 | Aug., 1972 | Touba.
| |
3739712 | Jun., 1973 | Duning.
| |
3802635 | Apr., 1974 | Drischel.
| |
3818824 | Jun., 1974 | Kloda et al. | 100/210.
|
3881409 | May., 1975 | Frigieri | 100/210.
|
3949659 | Apr., 1976 | Hunt | 99/349.
|
3965807 | Jun., 1976 | Baker.
| |
4213380 | Jul., 1980 | Kahn.
| |
4346653 | Aug., 1982 | Rodak | 100/73.
|
4601237 | Jul., 1986 | Harter et al.
| |
4667589 | May., 1987 | Bishop.
| |
4846054 | Jul., 1989 | Mange et al. | 99/495.
|
Foreign Patent Documents |
770153 | Oct., 1967 | CA | 100/37.
|
1395043 | Mar., 1965 | FR.
| |
274211 | May., 1930 | IT | 100/210.
|
59-55159 | Mar., 1984 | JP | 99/495.
|
544 | ., 1852 | GB | 100/37.
|
3998 | Nov., 1916 | GB | 100/37.
|
110601 | Oct., 1917 | GB | 100/37.
|
Primary Examiner: Hornsby; Harvey C.
Assistant Examiner: Gerrity; Stephen F.
Attorney, Agent or Firm: Spensley, Horn, Jubas & Lubitz
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation of application Ser. No. 406,768, filed on Sep. 9,
1989.
Which is a continuation-in-part of application Ser. No. 07/224,449, filed
Jul. 25, 1988 (now abandoned).
Claims
What is claimed is:
1. Apparatus for eliminating liquid fat from a formed, cooked ground meat
patty having a thickness of approximately 3/8", while maintaining the
structured integrity of the patty, the apparatus comprising:
a support member for supporting the patty and promoting the flow of liquid
fat away from the patty; and
means for compressing the patty against said support member, said means
comprising a plurality of rollers mounted in a housing for applying a
controlled rolling pressure which repeatedly traverses the patty in a
plane parallel to said support member,
wherein said housing is adjustable relative to said support member such
that said rollers and said support member are spatially offset such that
said patty is compressed less than about 50% of its thickness of its
cooked pre-processed thickness and the structural integrity of the patty
is maintained.
2. Apparatus as defined in claim 1 further comprising means for introducing
a non-fat liquid into the patty when rolling pressure is being applied to
a patty to displace additional liquified fat out of the patty.
3. Apparatus as defined in claim 2 wherein the non-fat liquid is supplied
to an upper surface of the patty.
4. Apparatus as defined in claim 3 wherein the non-fat liquid is supplied
in the form of a stream of droplets.
5. Apparatus as defined in claim 3 wherein the non-fat liquid is supplied
in a quantity sufficient to cause a substantial portion of fat initially
contained in the patty to be replaced by non-fat liquid.
6. Apparatus as defined in claim 2 wherein said rollers are mounted and
driven for causing the rolling pressure to travel on a circular path
across the patty.
7. Apparatus as defined in claim 6 wherein the patty has a center and the
circular path has an axis located in the vicinity of the center of the
patty.
8. Apparatus as defined in claim 1 wherein said rollers are mounted and
driven for causing the rolling pressure to travel on a circular path
across the patty.
9. Apparatus as defined in claim 8 wherein the patty has a center and the
circular path has an axis located in the vicinity of the center of the
patty.
10. Apparatus as defined in claim 1 wherein each of said rollers has the
form of a cone having a conical surface centered with respect to a cone
axis.
11. Apparatus as defined in claim 10 wherein said means for compressing
further comprise a plurality of shafts each supporting a respective roller
for free rotation about its cone axis.
12. Apparatus as defined in claim 11 wherein said rollers are oriented such
that the lowermost linear generatrix of the conical surface of each said
roller lies in a given plane parallel to said support member.
13. Apparatus as defined in claim 10 wherein said rollers are mounted to
travel over a circular path about a vertical axis and are oriented such
that the small diameter end of each said roller is directed toward the
vertical axis.
14. Apparatus as defined in claim 13 wherein: there are at least two pairs
of said rollers; said rollers of one said pair have a greater axial length
than said rollers of the other said pair; and wherein the large diameter
ends of said rollers of one pair are closer to the vertical axis than are
the large diameter ends of the other pair.
15. Apparatus for eliminating liquid fat from a formed, cooked ground meat
patty, while maintaining the structural integrity of the patty, the
apparatus comprising:
a support member for supporting the patty and promoting the flow of fat
away from the patty;
means for compressing the ground meat patty against said support member,
said means comprising a plurality of rollers mounted for applying a roller
pressure which repeatedly traverses the ground meat patty in a plane
parallel to said support member; and
means for introducing a non-fat liquid into the patty and wherein the
non-fat liquid is supplied to an upper surface of the patty and in a
quantity sufficient to cause a substantial portion of the fat initially
contained in the patty to be replaced by said non-fat liquid.
16. Apparatus as defined in claim 15 wherein said rollers are mounted and
driven for causing the rolling pressure to travel on a circular path
across the patty.
17. Apparatus as defined in claim 16 wherein the patty has a center and the
circular path has an axis located in the vicinity of the center of the
patty.
18. Apparatus as defined in claim 16 wherein each of said rollers has the
form of a cone having a conical surface centered with respect to a cone
axis.
19. Apparatus as defined in claim 18 wherein said means for compressing
further comprises a plurality of shafts each supporting a respective
roller for free rotation about its one axis.
20. Apparatus as defined in claim 19 wherein said rollers are oriented such
that the lowermost linear generatrix of the conical surface of each said
roller lies in a given plane parallel to said support member.
21. Apparatus for eliminating liquid fat from a formed, cooked ground meat
patty, while maintaining the structured integrity of the patty, the
apparatus comprising:
a support member for supporting the patty and promoting the flow of liquid
fat away from the patty; and
means for compressing the patty against said support member, said means
comprising a plurality of rollers mounted for applying a rolling pressure
which repeatedly traverses the patty in a plane parallel to said support
member,
wherein said rollers and said support member are spatially offset such that
said patty is compressed less than about 50% of its thickness of its
cooked pre-processed thickness and the structural integrity of the patty
is maintained; and
means for introducing a non-fat liquid to an upper surface of the patty,
wherein the non-fat liquid is supplied in a quantity sufficient to cause a
substantial portion of fat initially contained in the patty to be replaced
by the non-fat liquid.
Description
BACKGROUND OF THE INVENTION
The present invention relates to the preparation of formed ground meat
products, particularly to effect fat removal while maintaining the
products' structure and eating qualities.
My co-pending application, Ser. No. 07/224,449, filed Jul. 25, 1988,
entitled FAT REMOVAL FROM MEAT PRODUCTS describes a method and apparatus
for effecting fat removal from such products by establishing controlled
pressure and heating conditions under which the products' structure and
eating qualities are simultaneously maintained. As set forth in my
co-pending application, herein incorporated by reference, that invention
broadly relates to the field of treating meat products, and more
particularly, to a methodology which provides for the removal of fat from
the meat product, while maintaining the inherent pleasing texture of the
meat and without adverse impacting on such product's structural integrity.
While that invention, as well as the present invention, can be used with a
wide variety of meat products, both have particular applicability in
connection with processing hamburger patties.
Processing of hamburger patties is of key concern because that food is
extremely popular. People like the taste and texture of hamburgers and the
convenience of such a product. However, present literature has associated
heart disease with high blood cholesterol levels. Indeed, people with high
elevated blood cholesterol levels have been found to be at a higher risk
of developing heart disease than people who have relatively low blood
cholesterol levels. It has been shown that one factor contributing to high
blood cholesterol levels can be a high dietary intake of saturated fats.
The American Heart Association (the AHA) has recommended that in order to
reduce the risk of heart disease, individuals should reduce their daily
dietary intake of fats and cholesterol. Specifically, the AHA has
recommended (1) that individuals receive only 30% of their daily caloric
intake from fat with only 10% of that amount being derived from saturated
fat, and (2) that dietary cholesterol intake be kept below 300 milligrams
per day. Unfortunately, hamburgers sold at many fast food restaurants have
a high fat and cholesterol content.
While the prior art is aware of methods and related apparatuses for
treating meat products to remove fat, (see e.g. U.S. Pat. No. 3,949,659),
such methods and apparatuses suffer from a number of shortcomings. In
particular, many prior art methods for removing fat are not useful or
applicable to a product such as a hamburger or other structured,
patty-like meat product, because the methods employed would lead to a meat
product consisting of small pieces with a "chunk-like" texture or one
having the tough texture of leather (i.e., jerky). Neither of these is
structurally equivalent to a hamburger. Further, such products also
obviously differ significantly from a hamburger in terms of processability
and consumer acceptability.
As set forth in my co-pending application Ser. No. 07/224,449, one of the
goals was to reduce fat content yet maintain the shape, appearance,
texture and flavor of the product. That goal was achieved by a process for
treating a preformed meat product comprising the steps of (1) heating a
preformed meat product to a temperature which is sufficiently high to
liquify a portion of the fat contained in the patty, (2) applying a
specified amount of pressure to the meat product sufficient to cause a
substantial portion of the liquified fat contained within the meat product
to be exuded therefrom with minimal shape and textural and flavor changes,
and (3) removing the fat so exuded from the immediate vicinity of the meat
product. That application also discusses a method for enhancing the
juiciness and flavor of the meat product by injecting a liquid flavoring
solution into the patty.
While the method and apparatus described in my co-pending application
yields a cooked meat product having a low fat content and good eating
qualities, it is desirable to achieve further improvements in these areas
and to implement the method with an apparatus which is straightforward in
its construction and easy to operate.
SUMMARY OF THE INVENTION
It is an object of the present invention to improve fat removal while
maintaining flavor and structural integrity of a hamburger or similar
cooked meat product.
Another object of the invention is to achieve an increased degree of fat
removal over prior methods, while easily producing a tender and juicy
ground meat product.
A further object of the invention is to automate such treatment.
The above and other objects are achieved, according to this invention.
Broadly speaking, the present invention is directed to a method and
apparatus for eliminating fat from a formed ground meat product comprising
the steps of: bringing the product to a temperature at which a substantial
proportion of the fat contained in the meat is liquified; and compressing
the product against a support member only after the product has reached
the temperature at which a substantial portion of the fat contained in the
meat is liquified, by applying a rolling pressure which repeatedly
traverses the product in a plane parallel to the support member for a
period and at a pressure level sufficient to exude a substantial portion
of the liquified fat from the product, but at a pressure level low enough
to maintain the product's structure and eating qualities.
According to a preferred embodiment of the present invention, the formed
ground meat product, after having been brought to a temperature at which
the surface of the meat and structure has been "solidified" and at which a
substantial portion of the fat contained therein is liquified, is subject
to a periodic or continuous rolling compressive pressure while a liquid is
supplied to the top surface of the treated meat product. It has been
discovered that a key effect of the pressure is to cause sufficient
distension of the surface of the cooked meat product, so that the added
liquid is able to penetrate through the surface of the meat product and
migrate to the interior of the produce where it fills interstices left
vacant by fat that has already been exuded due to the application of the
rolling pressure. Continued applications of pressure displaces the added
liquid towards and through the product. As the liquid is forced through,
it displaces more liquified fat. As a consequence, improved fat removal
rates can be obtained without the need for higher pressure levels. While
the amount of fat removal is to some extent dependent upon the amount
present in the uncooked meat, it is possible with the process and
apparatus of the present invention to reduce the fat content of a typical
hamburger (one having 22% by weight fat initially) by at least 60% by
weight. Improved eating qualities are also obtained since at these low
pressures minimal compaction of the cooked meat patty occurs.
This method represents an improvement over my prior method in that more fat
can be removed at lower pressures and without additional compaction. A
further improvement is that by adding the liquid during the pressing step,
migration of the liquid to the interior of the meat patty maintains the
juiciness of the patty. Thus, the reintroduction of liquid back into the
body of the meat patty is highly simplified.
While it is believed that this invention would be applied most frequently
to ground beef patties, i.e., hamburgers, it can also be beneficially
applied to formed products made of other ground meats, including lamb,
veal, pork or chicken.
Preferably, application of the compressive pressure is begun essentially
immediately after completion of cooking, i.e., (i) when the product is
seared to some extent or is at least sufficiently cooked such that it
retains a defined patty-like appearance, and (ii) when the product has an
internal temperature suitable for serving and the fat is in a
substantially liquified state. At that time, the product is transferred,
if necessary, to a treatment station equipped with a compression device
according to the invention and the device is placed into operation to
effect fat removal in a manner to be described in greater detail below.
However, the fat removal procedure can be commenced at any time, even
during cooking, so long as a temperature has been reached in the product
at which a substantial portion of the fat contained in the product is
liquified and the structure of the product has been solidified. While not
to be bound by any theory, it is believed that the solidification of the
product is due to the greater structural integrity associated with meat
protein being denatured through cooking. Raw or minimally cooked meat
patties, on the other hand, are subject to tearing and breaking apart.
According to a preferred embodiment of the present invention, the rolling
compressive pressure is produced by circular movement of cone rollers
about an axis perpendicular to the top surface of the product. The
rollers, in effect, perform a movement with respect to each elemental
region of the product so that each elemental region is subjected to a
periodic compressive pressure alternating with intervals during which the
elemental region can expand.
The cone rollers are mounted so that a linear generatrix of each roller is
parallel to the top surface of the product, from which it follows that the
cone axis is inclined to that surface. Each roller is mounted to rotate
freely about its axis while being moved along a circular path about a
vertical axis located at least approximately at the center of the product.
With this arrangement, each roller can undergo essentially rolling motion
relative to the product. Sliding or dragging movement, which could tear
the product, is substantially eliminated since each roller is configured
and oriented such that its axis intersects the vertical axis of the
circular path at, or close to, the plane of the top surface of the meat
product being treated.
The desired rolling movement is achieved most simply by mounting each
roller to be freely rotatable about its axis. Then, as the rollers are
displaced along the circular path, rotation of each roller about its axis
is produced by contact of the roller with the formed product.
Because the compressive pressures are applied to the product by a circular
movement about an axis at or near the center of the product, any net
movement of the product in response to the rolling forces will be
circular, rather than translational. In other words, there will be minimal
tendency of the product to be displaced from the region beneath the
rollers. Thus, a particularly advantageous features of the invention is
that no complex holding devices are needed to hold the product in
position.
Although the conical roller system is particularly advantageous in this
invention, it has been found that to effectuate greater fat removal, two
different sized rollers are helpful. It has been discovered that a portion
of the cone-shaped roller adjacent the large outer diameter end is more
effective in promoting fat removal. It is believed that as the roller
diameter in contact with the patty is reduced, the band of direct
compression below the roller becomes sufficiently small such that the
liquid is mainly squeezed along the direction of roller movement rather
than also downwards and through the patty surface. Increased applied
pressure may not overcome this reduction in fat removal efficiency since
the small diameter end of cone may simply be pressed further into the
patty. This can result in destruction of the meat structure.
In order to offset this effect, devices according to the present invention
are provided, as noted above, with two diametrically opposed long rollers
positioned so that their large diameter ends act primarily on an exterior
annulus of the product and two diametrically opposed, equally large
diameter but short length rollers angularly equi-spaced between the long
rollers and located to act on the central portion of the product. So as to
prevent sliding or dragging movement which could tear the product, both
sets of rollers are configured and oriented such that their axes intersect
the vertical axis of the circular path at, or close to, the plane of the
top surface of the meat product being treated.
Preferably, the large diameter end of each short cone roller lies on a
circle passing through approximately the midpoint of the length of each
long roller.
According to a further feature of the invention, the roller surfaces can be
provided with a non-stick coating, such as PTFE, to facilitate cleaning.
In a device according to the present invention, heat lamps can be provided
to maintain the rollers, the support surface for the product and the
product itself at a temperature suitable to maintain the fat in a liquid
state and to maintain the product at serving temperature. Preferably, the
product should be maintained at a surface temperature of the order of
140.degree.-165.degree. F. The non-fat added liquid should be delivered at
a comparable temperature.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side elevational cross-sectional view of a preferred embodiment
of a treatment device according to the invention, taken along line I--I of
FIG. 2.
FIG. 2 is a cross-sectional plan view taken along the line II--II of FIG.
1.
FIG. 3 is a pictorial view illustrating the effect produced by the device
of FIGS. 1 and 2.
FIG. 4 is a graph illustrating fat removal rates for cooked hamburgers
placed on different support surfaces.
FIG. 5 is a graph illustrating fat removal rates for various roller
diameters.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 illustrate, in a cross-sectional elevational view and a plan
view, respectively, a preferred embodiment of a treatment system according
to the present invention. This system includes a support member 2 carrying
a flat perforated plate 4 on which a formed, ground meat product, such as
a hamburger patty, will be placed, preferably immediately after having
been cooked. In a typical operation the hamburger is cooked such that the
surface is seared to some extent or partially "browned." The internal
structure of the hamburger is also cooked to a stage of medium to medium
rare, i.e., minimal raw meat portion remaining.
Mounted above member 2 is a pressing device 6 composed of a housing having
a circular side wall 8 and a top plate 10. The lower edge of the housing
is provided with an inwardly extending rim 12 which supports a retaining
ring 14 provided to retain a hamburger patty in position relative to the
housing when device 6 is lowered toward support member 2. Retaining ring
14 is loosely supported by rim 12 so that after the lower edge of ring 14
comes to rest upon surface 4, device 6 can continue to be lowered.
Top plate 10 carries four support members 16 each providing a low friction
bearing for a shaft carrying a respective cone roller 20 or 22, each
roller 20, 22 being mounted so that the axes of all four roller shafts
intersect at least approximately at a single point which also contains the
vertical axis of symmetry, or center axis, of wall 8. Rollers 20 and 22
are positioned and oriented so that their lowermost edges all lie
substantially in a common horizontal plane which contains the
above-mentioned single point.
Cover plate 10 of device 6 is provided with a circular trough 24 having
associated outlet tubes 26 for the delivery of non-fat liquid, and plate
10 is supported by a shank 30 mounted in a bearing 32 to permit shank 30
and device 6 to be rotated about the vertical center axis of wall 8.
Bearing 32 carries a motor 34 coupled to shank 30 in order to produce such
rotation.
Bearing 32 is, in turn, supported by a stand 36 in a manner to be
vertically movable relative thereto. Coupled between stand 36 and bearing
32 is a force applying device 40, which may be pneumatically actuated, for
displacing bearing 32, and the components which it supports, in a vertical
direction and applying a selected force thereto.
In the operation of the device illustrated in FIGS. 1 and 2, a cooked,
preformed, generally flat hamburger patty is placed on surface 4 and, if
necessary, surface 4 is brought into the position illustrated in FIG. 1
below device 6. This may be accomplished, for example, by mounting support
member 2 for horizontal movement from a loading or cooking station to the
location below device 6. Motor 34 is placed into operation to rotate
device 6 and liquid is slowly added to trough 24 as unit 40 is actuated to
lower device 6 so as to bring rollers 20 and 22 into contact with the top
surface of the hamburger patty and to apply a selected compression force
to device 6. Thus, rollers 20 and 22 roll upon the top surface of the
hamburger patty applying a compressive pressure while following a circular
path about the central axis of wall 8. The bearings in support 16 are low
friction devices constructed to permit free rotation of rollers 20 and 22
as a result of their contact with the top surface of the hamburger patty.
During the period of this operation, the hamburger patty is constrained in
place on perforated plate 4 by retaining ring 14 which is retained in
axial alignment with wall 8.
The action of rollers 20 and 22 on a hamburger patty is depicted in the
schematic diagram of FIG. 3.
As roller 20 or 22 advances to the left, as indicated by arrow 50, the
roller rotates in a counterclockwise direction, as indicated by arrow 52,
and presses downwardly on a hamburger patty 54. Ahead of the advancing
compression front, liquid will be forced downwardly between interstices in
patty 54, as represented by arrows 56, resulting in the expulsion of
liquid, as represented by arrow 58. In addition, some liquid will be
forced upwardly, as represented by arrow 60, toward the top surface 62 of
patty 54. In the region of maximum compression, some liquid (some of which
may be from the patty itself and another portion being sprayed or dripped
on from tubes 26) will be forced sideways, as represented by arrows 63,
predominately in the direction away from the direction of advance of the
compression force because expansion of the patty behind the roller creates
a region of reduced pressure. At the same time, some liquid is forced
downwardly, as indicated by arrow 64. The liquid which is displaced toward
the right will have a displacing effect on liquid in interstices
downstream thereof, as indicated by arrows 66. Behind the roller, the top
surface 62 of patty 54 is stretched and given a convex curvature, which
substantially facilitates the downward entrance and movement of the added
liquid through the seared top surface, as indicated by arrow 68. This
liquid serves to refill the emptied interstices so that on subsequent
rolling it is easier to continue to displace the fat/non-fat liquid
mixture in the interstices. Consequently, the liquid supplied to top
surface 62 from tubes 26 will significantly enhance removal of fat from
patty 54.
Because the added liquid from tubes 26 is controlled as to its
constituents, flavorings, spices, etc. can be added to the patty. In the
preferred embodiment, the added liquid is substantially fat-free.
Above a minimum applied force, the net effect of the gentle moving pressure
produced by rollers 20 and 22 is a significant downward movement of liquid
masses. In addition, liquified fat or other meat liquids which initially
exude onto top surface 62 from the interior of patty 54 are also
subsequently forced downwardly by the action of rollers 20 and 22 and the
expansion movements of patty 54.
According to a principal aspect of the invention, the rotating compression
forces are applied to the product in a manner to achieve optimum fat
removal without damaging the product, as by tearing it. It has been found
that achievement of this combination of results is affected by three main
parameters: the rate of rotation of the compression forces; the magnitude
of the force; and the maximum diameter of the roller cones.
The rate of rotation should be kept low enough to avoid tearing the
product, but high enough to effect substantial fat removal in a reasonable
time period. It presently appears that a rate of rotation of 7-12 rpm
produces optimum results. At this rate, the compression force application
can be limited to a period of the order of 90 seconds. The compression
force is particularly selected to maximize fat removal while preventing
either permanent compaction (toughening) or tearing of the product.
The compression force level is selected, as a function of the area of
contact between the rollers and the top surface of the formed product, to
cause the product to be resiliently, rather than permanently, compressed
at the large diameter end of the conical roller; and to prevent tearing of
the patty surface at the sharper diameter end of the conical roller. Under
preferred conditions, after a roller has moved past a given elemental
region of the product, that region should return approximately to its
original thickness so that the product behaves somewhat like a sponge from
which entrapped liquid is expelled, primarily downwardly, during
compression and into which liquid is absorbed, primarily from the top
surface, during subsequent expansion.
The cyclic compression forces also engender frequent movements between
adjacent horizontal strata of the product, resulting in improved texture.
If cones having a maximum diameter in excess of about 3 inches are used at
a pressure sufficient to remove substantial quantities of fat, there is a
tendency for patty compaction to occur. On the other hand, if narrow cones
are used having a maximum diameter of less than about 1 inch at similar
pressures, tearing of the patty becomes an issue. Further, when using both
an acceptable diameter cone and an acceptable applied pressure, it has
also been found that less fat is eliminated from the meat in the area
below the narrower end of the cone. It is hypothesized that towards the
narrow end of the cone the region of direct downward pressure becomes so
small that little fat is eliminated from the meat since the majority of
the fat below this high pressure region is being displaced sideways.
In order to overcome this reduced fat removal in the center of the patty
(towards the apex of the cone where the diameter is reduced), use is made
of four cone rollers. Each of these cones has a maximum diameter (i.e., at
the large end) of the order of 1 to 2 inches, and preferably about 1.5
inches. Two of the cones are approximately half the length of the other
two and the cones are alternatively mounted via support members 16 on the
top plate 10 so that they are displaced towards the center of the axis of
rotation. The two longer roller cones act with respect to fat removal
primarily on an external annulus of the product, and the two shorter
roller cones act with respect to fat removal on the central region of the
product. In this manner fat can be eliminated approximately equally
throughout the entire patty volume. Obviously, a variety of cone
configurations and numbers of cones can be used to achieve the above
mentioned result provided at least one larger diameter, but shorter length
cone is displaced towards the center axis of rotation to effectively act
on this region.
As the rolling compression force is applied, non-fat liquid is supplied to
the top surface of the product, and that liquid is urged through the top
surface to the interior of the product, where it fills interstices left
vacant by exuded fat. Intrinsic non-fat liquid in the patty does to some
extent serve this purpose. However, the amount of such liquid is
frequently not sufficient to aid in the removal of significant amounts of
fat and yet maintain juiciness.
The supply of non-fat liquid permits a reduction in the level of
compression pressure required to achieve a given percentage of fat removal
by filling the interstices left vacant by exuded fat. This pressure
reduction substantially aids in maintaining the eating qualities of the
product.
In addition to promoting the removal of fat, the delivery of substantially
non-fat liquid to the top surface of the product also serves to enhance
and reestablish the products juiciness, which would obviously be reduced
during the pressing out of fat and non-fat liquid from the meat. This
unexpected ability of liquid to penetrate the cooked hamburger surface
during the application of pressure therefore serves two important function
in this invention--to simultaneously enhance fat removal and to increase
the juiciness of the patty.
These benefits of supplying non-fat liquid are optimized if this liquid is
supplied for substantially the entire duration of the application of the
compression force. However, the juiciness of the product is particularly
enhanced if the supply of non-fat liquid to the top surface is continued
for a period of time after the compressive force has been substantially
decreased. This is achieved because the last added liquid is not forced
out, and thus remains in the body of the patty.
According to preferred embodiments of the invention, as non-fat liquid
continues to be supplied to the top surface of the meat patty, a force
level 8-12 pounds (corresponding to an approximate pressure level of about
4 psi) is applied for the first 60-70 seconds of the quality enhancing
treatment and the force level is then reduced to a value of 2-3 pounds
(corresponding to an approximate pressure level of 1 psi) during the
remainder of the treatment, which serves primarily to allow non-fat liquid
to be added to the product without being subsequently squeezed out.
The basis of the present invention can best be understood by reference to
the following examples which are intended as illustrations only and are
not to be construed so as to limit the invention as set forth in the
claims and specifications.
EXAMPLE 1
As set forth in my co-pending application Ser. No. 07/224,449, Example 1
demonstrates the unexpected ability of applied rolling pressure to remove
substantial quantities of fat from a cooked preformed hamburger patty
while maintaining its inherent shape, structure and eating qualities.
The meat employed in Example 1 is ground beef having an initial fat
concentration that is approximately 20% by weight. The initial fat
concentration is determined by laboratory analysis based upon weight. The
ground beef is formed into circular hamburger patties weighing in the
range of from about 108 to about 114 grams. The hamburger patties have a
pre-cooked diameter of 11.5 to 12 centimeter. After the ground beef is
formed into patties, the patties are frozen in a commercial freezer for at
least 12 hours prior to cooking.
The frozen hamburger patties are removed from the freezer and cooked,
without thawing, on an electric griddle set at 163.degree. C. During
cooking the hamburgers are turned over frequently (at least four times) to
ensure even heating throughout the hamburger patty. The temperature of the
cooked hamburger patty is measured by a fast-reacting direct-reading
electronic thermocouple. The electronic thermocouple is inserted into the
hamburger patty to a location approximately halfway between the upper and
lower surfaces of the hamburger patty. The temperature which registers on
the electronic thermocouple is the final cooking temperature set forth in
Table 1.
Once the hamburger patty reaches the desired temperature, it is subjected
to a pressing step in the following manner. The cooked hamburger is
removed from the electric griddle and placed immediately on a flat board
which is inclined from the horizontal at an angle of about 12.degree.. A
rolling band of pressure is applied to the cooked hamburger patty by
rolling a cylindrical drum over the top surface of the hamburger patty.
The fat/water mixture exuded from the hamburger patty during the pressing
process is collected in a groove around the edge of the board and emptied
into a measuring cylinder. In this manner, the total quantity of fat and
non-fat moisture removed from the hamburger patty during the pressure
application is determined. The cylindrical drum is rolled across the
hamburger patty five times. The quantity of fat rendered during the
cooking process is added to the fat eliminated during compression to
define the total fat removed during the entire process.
The texture of the resultant cooked, pressed hamburger patty is determined
organoleptically.
The above-described experiment was conducted on a number of individual
hamburger patties cooked to different temperatures and pressed at
different pressures. The results of the experiment are set forth in Table
1 herein. This table is similar to the one in my copending application,
but also includes additional information.
As shown in Table 1, it is possible at very low applied rolling pressure to
remove substantial quantities of fat from a cooked preformed hamburger
patty. This result is particularly unexpected in view of the fact that in
prior art processes, much higher pressures had to be used. Further,
maintaining the hamburger's inherent shape, structure and eating qualities
can be attributed to the unexpected fact that the hamburger behaves
somewhat like a "sponge" under the low rolling pressures required for the
elimination of substantial quantities of fat from the cooked preformed
patty.
The cooking and pressing action does, however, eliminate liquid (both fat
and non-fat liquid) from the hamburger as indicated in column 7 of Table
1. For many of the trials (Runs 1 to 7, 11 and 13) the total percent
liquid eliminated (column 7, which is the sum of column 5 and 6) from the
hamburger by cooking, pressing and evaporation approximates the percent
water lost only by evaporation during the cooking of "well done"
hamburgers (31.6% by weight for Runs 9 and 10). Thus, the "juiciness"
sensation of the processed (by pressing) hamburger, although reduced, can
be considered to be still be within the range of general acceptance.
Nevertheless, many consumers desire "juicy" hamburgers and it is for this
reason that in a preferred embodiment of the invention, liquid is returned
to the hamburger during or after processing to re-establish the
anticipated juiciness of a regular (not "well done") hamburger.
TABLE 1
__________________________________________________________________________
Total
Water Liquid
Removed
Liquid
(water &
By Removed
fat) lost
Final
Avg. Evapt'n
During
by evap,
% Cooking
Applied
During
Pressing &
press &
%
Run
Start
Temp.
Pressure.sup.1
Cook.sup.2
Cooking.sup.2
cook.sup.2
Fat
No.
Fat
(.degree.C.)
(psi)
(%) (%) (%) Removed
ORGANOLEPTIC DESCRIPTION
__________________________________________________________________________
1 18.3
55 2.5 23.5 14.0 37.5 39 Soft, easy to chew
2 18.45
50 2.5 16.7 15.7 32.4 42 Soft, easy to chew
3 17.6
40 6.9 4.6 14.5 24.1 39 Not completely cooked
4 17.6
47-50
6.9 13.5 22.0 35.5 65 Soft, easy to chew
5 18.45
50 6.9 12.7 21.5 34.2 60 Soft, easy to chew
6 18.45
48-55
6.1 15.0 19.4 34.4 54 Soft, easy to chew
7 18.3
50-55
6.9 22.9 17.0 39.9 46 Firmer, easy bite
8 17.6
55-60
6.9 -- 19.0 -- 58 Firmer, easy bite
9 17.6
70 6.9 31.6 11.0 42.6 43 Firmer bite; dry taste
10 17.6
70-75
6.9 31.6 12.4 44.0 47 Firmer bite; dry taste
11 20.4
50 8.9 12.6 25.0 37.6 68 Firmer, easy bite
12 20.4
55 8.9 19.0 20.0 39.0 57 Firmer bite
13 20.4
55 8.9 15.4 22.7 38.1 62 Firmer, easy bite
14 18.3
50-55
10.2 22.0 20.3 42.3 57 Firmer bite, not tough,
dry taste
__________________________________________________________________________
.sup.1 Mass average applied pressure based on a rolling contact surface 2
cm wide with an aftercooking diameter of 9 cm.
*Not measured
.sup.2 Percent based on starting hamburger weight.
EXAMPLE 2
Cooked hamburgers behave somewhat like a "sponge." Their interstices are
filled with liquid fat and the meat structure is sufficiently flexible to
be able to withstand a low applied pressure without permanent destruction.
As a consequence, it is possible to eliminate substantial quantities of
fat from the patty and still maintain its inherent shape, structure and
eatability provided prior to pressure application, the heated hamburger is
placed on a surface designed to both support it and facilitate the
immediate separation of any fat exuded during the pressure application.
In order to demonstrate this discovery, frozen 1/4 lb. hamburger patties
(43/4 inch diameter and 3/8 inch thickness) having a starting fat content
of about 22% by weight were broiled on an electric griddle (set at
350.degree. F.) under identical conditions (% cooking loss--water and
fat.--27-28%). These hamburgers were then processed either on a solid flat
surface or on a perforated plate. The hamburgers were pressed at various
applied pressures according to the following techniques:
(1) When a solid flat surface was used, hamburgers were placed directly on
this surface which was in turn supported on a scale. The top surface of
the hamburger was then covered with a second solid flat surface and a
force (measured on the scale) was applied to the top surface, thus
squeezing the hamburger between these two flat solid surfaces. After the
applied force was released and the hamburger removed, the exuded fat
quantity left on the lower flat surface was recorded together with the
pressed and non-pressed weights of the hamburger and the fat quantity
rendered during cooking. Percent fat removed during processing could
therefore be estimated. This experiment was repeated at increasing forces
until the patty was permanently destroyed. The applied pressure was
calculated from the applied force divided by the cooked patty surface area
(14 in..sup.2) and the results are shown in FIG. 4 as "Flat on Flat."
(2) The apparatus described in Example 3 was used for the perforated plate
experiments with the pressure being applied to the hamburger either by a
flat solid surface or a rolling device (13/4 in rolling drum) Percent fat
exuded during processing was measured at various applied increasing
pressures, until once again the patty structure was permanently modified.
Applied pressure when using the flat solid surface was calculated as
above. Applied pressures reported for the roller experiments were
estimated as the mass average pressure from the pressures applied to
different sectors of the circular hamburgers, each having a width equal to
the roller circular perimeter in contact with the meat at a particular
applied pressure (0.7 inch at 2.5 psi; 0.8 inch at 5 psi; 1.2 inch at 8
psi). Results are presented in FIG. 4 as "Flat On Perforated Plate" and
"Roller on Perforated Plate."
As can be seen from FIG. 4 at similar applied pressures, substantially more
(plus 13% at 3.0 psi; plus 43% at 7 psi; plus 37% at 11 psi) fat is
separated from a patty placed on a perforated plate as compared to a flat
solid surface. The hamburger behaves somewhat like a "sponge" since if the
pressure is released while the patty is still in contact with exuded fat
(as in "Flat on Flat") a substantial amount of fat is sucked back into the
patty resulting in a lower percent fat removal. As shown in FIG. 4, when a
perforated plate is used not only can a quality patty be produced, but
because the exuded fat is directed away from the patty before it can be
drawn back into the structure, substantially more fat can be eliminated.
EXAMPLE 3
Since rolling pressure is particularly effective for fat removal under
gentle conditions, a series of experiments were undertaken using different
roller diameters and applied pressures to determine conditions under which
maximum fat elimination could be achieved while maintaining the
hamburger's shape, structure and eating quality.
Standard frozen 1/4 lb. hamburger patties (43/4 in. diameter and 3/8 in.
thickness) having a starting fat content of about 22% by weight were cut
into a square shape (so that the rolling pressure could be applied across
a constant width cooked hamburger) and broiled on an electric griddle (set
at 350.degree. F.) under standard, repeatable and identical conditions (%
cooking loss [water and fat] 27-28%). Each hamburger, immediately after
having been cooked, was placed on a horizontal perforated plate mounted in
a support structure and a funnel was placed beneath the perforated plate
to direct liquid from the hamburger into a measuring cylinder. The entire
structure was placed on a scale so that the force applied to the rollers
could be measured. Various roller diameters were employed, percentage of
fat removal was measured, and the texture of each resulting hamburger was
tested in a subjective and objective manner. Fat removed values reported
were based on the fat collected in the measuring cylinder, the weight
difference of the patty before and after pressing and the fat rendered
during cooking.
FIG. 5 is a diagram which depicts the relation-ship between percentage of
fat removed and roller diameter (including a flat plate--a very large
diameter roller) at various applied compression forces. With a particular
sized roller, several different experiments were repeated at increasing
applied forces, until a maximum in fat removal was achieved. This maximum
in fat removal occurred either when the hamburger structure started to be
destroyed by cutting or tearing (as occurred for rollers of diameters less
than about 5 inches due to the penetration of the roller into the
hamburger) or when little further fat removal could be achieved without
permanently distorting the hamburger structure. Line 74 on FIG. 5 is a
locus connecting approximately points of maximum fat removal for various
rollers when maximum pressure for the particular diameter roller was being
applied. FIG. 5 additionally includes a number of data points representing
different compressive force values which were tested and all the data
shown on FIG. 5 are summarized in Table 2.
TABLE 2
__________________________________________________________________________
Operating Conditions
Force Applied Percent
Organoleptic Evaluation
Run
Roller
To Roller
Applied
Fat Taste Percent
No Diameter
or Plate
Pressure.sup.1
Removed
Comments Compaction.sup.2
__________________________________________________________________________
1 1/2" 5 lb 50 Softish 9
2 1/2" 10-12 lb
6 psi
57 Soft/easy bite; breaking up on
13
bottom
3 1" 5 lb 52 Soft/easy bite 13
4 1" 10 lb 54 Soft/easy bite 9
5 1" 15-20 lb
6.3
psi
63 Soft/easy bite; breaking up on
12
bottom
6 13/4"
5 lb 47 Softish 9
7 13/4"
15 lb 56 Soft/sl. firm 13
8 13/4"
30 lb 8.6
psi
66 Harder/more compact. Breaking
26
up on bottom
9 5" 15-20 lb 47 Soft/easy bite 13
10 5" 40 lb 63 Sl. soft/firm some compaction
26
11 5" 60 lb 10 psi
77 Firm/compact; breaking up on
31
bottom
12 Flat 90 lb 10 psi
55 Firmer/compact 30
13 Flat 160 lb 17.8
psi
64 Hard/compact 39
__________________________________________________________________________
.sup.1 For various rollers limiting applied pressure estimates based on
roller penetrating 3/16" into cooked hamburger. For flat pressure
application, pressure calculated as applied force/cooked hamburger surfac
area. (9 in.sup.2)
##STR1##
Whereas the experiments were performed by varying the force applied to a
given roller, it is clear that the relevant parameter that affects fat
removal rates is the intensity of the applied force or the force per
contact area between the roller and the hamburger. Since the contact area
for rollers increases with increased applied force, the pressure at
rupture was estimated by assuming that rupture of the hamburger surface
occurred when the roller penetrated at least 3/16" into the hamburger
(representing 50% of the cooked non-processed hamburger thickness).
Broken line 76 depicts a boundary region above which a noticeable
toughening and compaction of a hamburger patty is produced. The boundary
represented by line 76 is based on a number of factors including
organoleptic evaluation and percent compaction of the hamburger after
pressing. From FIG. 5, it can be seen that fat removal levels of the order
of 60-65 weight percent can be achieved, without tearing or toughening a
hamburger patty with rollers having a maximum diameter in the range of 1-2
inches and compression pressures in the range of 6 to 9 lb/in, Further,
additional fat can be removed, to about 70 weight percent, while still
achieving many of the eatability factors.
Furthermore, it can be seen that as the roller diameter drops below 1 inch,
a decrease in fat removal is observed. It is for this reason that at least
two sizes of cones are used in the present invention. The large diameter
shorter cones offset the fat removal inefficiencies of the small diameter
region of the longer cones, so that the cooked patty can be essential
equally processed across its entire surface at acceptable low pressures.
EXAMPLE 4
Several experiments were carried to demonstrate the influence of supplying
a non-fat liquid to the top surface of hamburger patties simultaneously
with the application of rolling compressive pressures. A device having a
form as shown in FIGS. 1 and 2 was employed. Hamburgers as described above
were broiled under standard conditions and each hamburger was then placed
on a horizontal perforated plate as described above, and liquid eliminated
from the hamburger during the application of compressive forces was
collected in a measuring cylinder. In one procedure, non-fat liquid was
supplied to the top surface of a hamburger patty, while in a second
procedure, no liquid was added. In each case, the compression force was
brought to a fixed value of 10 lbs. (equivalent to a compressive pressure
of about 3.7 psi) selected to produce a high level of fat removal and was
maintained at that value for a period of 70-80 percent of the total
treatment time. Then, the force was reduced to approximately one-third of
its initial value during the remaining 20-30 percent of the force removal
time, the purpose of this reduction being to permit non-fat liquid (when
used) being introduced into the hamburger to be retained.
The result of these experiments are shown in Table 3. Several unique
features of the invention are demonstrated in these results. First in Run
1, even though the applied pressure is only approximately 3.7 psi, the
addition of non-fat liquid to the hamburger during pressure application
produces significant fat removal (67 wt. %). An applied pressure of 6 to 9
psi would be required to eliminate the same percent fat when no liquid is
added. (See FIG. 5). Thus, there is substantially less compaction. Second,
even though substantial quantities of fat are removed (when non-fat liquid
is added), the weight of the cooked meat remains essentially unchanged
indicating that the non-fat liquid has substantially replaced the fat
liquid lost during pressing. Consequently the hamburger maintains its
"juiciness." This is in contrast to Run 2 where because the liquid pressed
out is not replaced, the weight of the meat after pressing is lower than
the starting cooked weight, and the hamburger has a dryish taste.
TABLE 3
__________________________________________________________________________
Cooked Wt. of
Wt. of Meat
Run
Liquid
Wt. of Fat
Total %
Meat Before
After
No Addition
Pressed Out
Fat Removed
Processing
Processing
Comments
__________________________________________________________________________
1 Yes 12.5 gms
67% 80 gms 78 gms Soft/juicy
2 No 6.5 gms
46% 79 gms 68 gms Soft/easy bite
dryish tasting
__________________________________________________________________________
While the description above refers to particular embodiments of the present
invention, it will be understood that many modifications may be made
without departing from the spirit thereof. Typically, the present
invention causes at least about 33% by weight of the fat originally
present to be exuded. The exact amount of fat removed is of course
dependant upon the amount initially present in the meat and the natural
variability of meat quality. As set forth above, however, the present
invention can remove over 60% by weight of the fat originally present in a
hamburger having an initial fat content of about 22 weight percent. Thus,
removal of at least 50% of the fat initially present can readily be
achieved by the present invention. Yet other modifications are also within
the scope of the present invention. For example, while perforated plate 4
is used as the support for the hamburger, other support surfaces are
within the scope of the invention. Further, still while perforated plate 4
is generally flat, other means can be used to direct the exuded fat away
from the meat including inclined surfaces and the like. The accompanying
claims are intended to cover such modifications as would fall within the
true scope and spirit of the present invention.
The presently disclosed embodiments are therefore to be considered in all
respects as illustrative and not restrictive, the scope of the invention
being indicated by the appended claims, rather than the foregoing
description, and all changes which come within the meaning and range of
equivalency of the claims are therefore intended to be embraced therein.
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